Slotted structural elements that are used in the construction and electrical industries for light structural support, often for supporting wiring, plumbing, or mechanical components such as air conditioning or ventilation systems.
One, less expensive type of slotted structural element is a channeled strut, which is usually formed from metal sheet, folded over into an open channel shape with inward-curving edges to provide additional stiffness and as a location to mount interconnecting components. Struts can also be constructed from fiberglass. Struts sometimes have holes of some sort in their bases, to facilitate interconnection or fastening of the struts to underlying building structures.
For more mechanically demanding applications, extruded structural elements are often used. For example, aluminum can be extruded to form slotted structural members having various precise shapes and sizes, including structural elements that include slots formed in more than one longitudinal surface.
One common variety of slotted structural element is the “T-slotted” structural element, where the term “T-slotted” is used to refer to any structural element that is uniform in cross section along its length and includes at least one longitudinal slot that is open to a surface of the structural element, and is widened below the surface so that the slot is covered by an overhang on each side. T-slotted plates, bars, T-slotted extrusions and table surfaces are used in a wide variety of industries. Entire frameworks for machinery are constructed using many different sizes and shapes of T-slot elements. Metal and wood working equipment incorporate T-slotted tables/work tops to secure work pieces while machining, grinding, welding and performing other processes. These T-slotted elements are made from steel, aluminum, plastic and fiber glass.
A T-slotted extrusion is so-called because it has a groove or slot in the shape of an inverted letter “T” cast, extruded, machined or planed in the upper surface of its structure. T-slotted extrusions can take the shape of a table, plate, bar or tube with an undercut below the top plane. In the aluminum structural frame industry, the groove or slot can be found on all sides of a slotted extrusion. The combined slot and undercut results in a shape, from an end view of the member, approximately resembling an inverted block-letter capital T.
An important advantage of using standardized T-slotted structural elements in construction is that there are many options available for rapidly and easily connecting the structural elements together, and for connecting other items to the T-slotted structural elements, using various specialized fasteners and bolts. This allows T-slotted structural elements to be assembled into a desired structure very rapidly, with minimal tools, and with only moderately trained labor, thereby reducing costs significantly for many applications. Typically, an assembly of T-slotted struts or extrusions can also be modified or added onto relatively easily if needed. The only alternative to slotted strut channels and extrusions for most applications is custom fabrication using steel bar stock and other commodity components, requiring welding or extensive drilling and bolting, which has none of the above advantages.
In addition to structural framing for machines, T-slotted structural elements are also used in jigs and assembly fixtures. The T-slots allow components to be bolted anywhere along the length of the structural elements. This allows components to readily locate or hold a part in place while it is being machined or being attached to another part. The installation and adjustment of such slotted components, and the quick disassembly of the same components, provide many variations for other uses. In situations that require a part to be held in position, the need to attach a part holding device or clamp to a T-slotted structural member is necessary. Typically, such clamps have been fixed to the end of the structural member. However, because final adjustments and a variation in the part that needs to be held or clamped is common, it would be advantageous if a clamp could be positioned and re-positioned anywhere along the T-slotted structural element.
Typically, a strut or extrusion clamp includes a compression jaw and an anvil jaw that are arranged in an opposing relationship with each other. The compression jaw is usually located at an end of a structural element, and is typically mounted to a force-creating component, which can be guided by and/or mounted to a variety of materials having a variety of shapes. In many clamps, the force-creating component is a screw that is manually rotated to advance the compression jaw toward the anvil jaw, so as to impart a force on the object to be clamped, which is transmitted from the object to the anvil jaw. Note that the anvil jaw is also referred to herein as the “clamp stop,” while the compression jaw and the components that impart the force to the said compression jaw is also referred to herein as the “clamp block.”
Unfortunately, traditional clamps used for interconnecting structural members such as strut channels and slotted extrusions suffer from several deficiencies. Typically, the clamp block is rigid and fixed at an end of a structural member, and is not free to move along the structural member. The clamp block is typically threaded to a pipe that is fastened, pinned or ultimately welded to the structural member.
Also, known clamp blocks and clamp stops are typically complex, and require advanced manufacturing techniques to construct, and the number of clamp blocks and clamp stops that can be attached to a given structural member is very limited. In addition, structural members to which clamps are attached are typically dedicated to the function of the clamp and cannot be easily used in other applications, due to the fastening or welding of the clamp components to the said structural member and/or structural changes made to the structural member itself to accommodate the clamps. As a result, other structural members and/or additional accessories are not easily attached to the clamp structure, which limits the function of the clamp.
Known strut clamps also set a lower-limit on the cross-sectional size of the strut channels with which they are compatible, typically requiring U-shaped channels of the larger variety, because smaller or more shallow U-shaped channels do not provide sufficient cross-sectional area for attachment of known clamp designs.
What is needed, therefore, is a clamp for a T-slotted structural element that can be easily and flexibly positioned along the structural member, can be used with slotted structural members of smaller cross-section, and does not require permanent attachment to a pipe, bar, or other structural member.